Smith Chart: how to plot a large SWR value

[tR|GG3rX]

how to calculate swr in smith chart

how to plot a large standing wave ratio (SWR) value (around 43) in smith chart? i've obtained this value during my lab session.

the phase angle is 46.7 degrees (plotting this is not a problem).

thanks in advance...

 

[djalli]

vswr smith chart

how to plot a large standing wave ratio (SWR) value (around 43) in smith chart? i've obtained this value during my lab session.

the phase angle is 46.7 degrees (plotting this is not a problem).

thanks in advance...

SWR has not angles. Phase angle 46.7 degrees is of reflection coefficient gamma?

You possibly have done some error somewhere. I agree with glenjoy SWR quite too much 43.

See fig. I am attaching for formulas.

 

[tR|GG3rX]

howto plot smith chart

yeah, i think it's a mistake also. i'll redo my lab.
the maximum SWR can be is only 10 right?

thanks guys.

 

[djalli]

smith chart swr

yeah, i think it's a mistake also. i'll redo my lab.
the maximum SWR can be is only 10 right?

thanks guys.

Try |gamma| to be 0.9545 what is SWR?
Try |gamma| to be 1 what is SWR?
just calculate them.

Let me make them for you:
if |gamma| is 0.9545 then SWR is 43.
if |gamma| is 1 then SWR is infinit.

So SWR maximum can be up to infinit.

The only thing I opposed number 43 because it is hard to believe for you in school lab to get that kind of SWR Standing Wave Ratio not that value 43 is not correct.

In lab you are supposed to do things are practical things in real life industry. In real life industry SWR is maximum 3.0(lower the better) also mentioning phase of SWR made my mind to come to a conclusion you have do some error either in calculating or measuring.

Do not worry! Successes are built upon failures.

 

[sergio mariotti]

In some cases high Gamma are wanted, think to a VNA measurement of an inductor.

If you want to plot it on a Smith Chart , the main problem is the associated uncertainty ellipse. Try to propagate (calculate) the uncertainty and be surprise of how large became!